Determining the Effects of Organic Chemical Mixtures and Wastewater on DNAPL Migration
EMSL Project ID
25596
Abstract
DNAPL spill and water discharge scenarios at the ground surface may significantly impact DNAPL migration, entrapment, and subsequent effects on groundwater quality. A notable example is the Hanford Site in Washington, where organic chemical mixtures containing carbon tetrachloride (CT) were discharged with large volumes of wastewater to the subsurface at three major disposal facilities (216 Z-9 Trench, 216-Z-1A Tile Field, and 216-Z-18 Crib). Significant efforts have been made to determine how much CT remains as a source in groundwater, and in the vadose zone, but considerable uncertainty remains. We postulate that the effects of DNAPL mixtures and wastewater, using site-specific materials, must be accounted for before an accurate site-specific conceptual model for DNAPL migration and distribution at the Hanford is possible. We propose three different transient experiments using a 2-D flow cell to determine the effects of DNAPL mixtures and wastewater on DNAPL distribution. Pure CT and four DNAPL mixtures will be used in the experiments. The first mixture (MIX1) is representative of DNAPL mixtures disposed at the Hanford site. The other mixtures consist of three binary fluids (MIX2, MIX3, and MIX4) discharged at the 216-Z-9 trench from the Recuplex process. All experimental conditions except for the used DNAPL mixture type are identical. In the three experiments, pure CT, MIX1, and a sequence of MIX2, MIX3, and MIX4 will be released on top of the flow cell, respectively. The primary differences between MIX1 and the other mixtures are viscosity and interfacial tension. A key component of this approach is using realistic NAPL mixtures, wastewater, and Hanford sediments. Information from these experiments will be integrated into the STOMP simulator to simulate the distribution and migration of DNAPL mixtures in heterogeneous porous media for different DNAPL and water discharge histories at the Hanford Site.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2007-06-01
End Date
2010-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Enhanced remedial amendment delivery through fluid viscosity modifications: Experiments and numerical simulations
Zhong, L., M. Oostrom, T.W. Wietsma, and M.A. Covert. 2008. Enhanced Remedial amendment delivery through fluid viscosity modifications: Experiments and numerical simulations. J. Contam. Hydrol. 101: 29-41, doi:10.1016/j.jconhyd.2008.07.007.